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Pro-2006 backlight repair

I figured it was about time to replace the electroluminescent EL backlight on my Pro-2006 scanner. I think there used to be a pictorial somewhere, but I couldn’t find it, so I decided to grab some pictures while I swapped in a new one. Click any image to enlarge.

First, remove the antenna and the 4 screws holding the case to the back of the radio. No need to remove the battery by the way, not sure what I was thinking…

Next, pushing from the back, slide the radio forward in the case, about 1/8″ or so. Tilt the top cover up, reach in and disconnect the speaker header from the circuit board, and remove the cover.

With the top cover removed, unplug all the connection headers from the top of the circuit board. Flip the scanner over, remove the bottom cover, unplug the header from the bottom of the circuit board, then use a phillips head screwdriver and remove the braided jumpers from the frame.

With all wiring disconnected from the circuit board, remove the two screws each side that are holding the face in place.

The face should come right off.

To get the circuit board off, use your soldering iron to unsolder and bend out of the way the ground wire coming from the volume and squelch pot assembly. I used a pair of needle nose pliers to lift it off and over to the side after heating up the pool of solder it is in.

Next, remove the six phillips head screws holding the circuit board in place.

To get the circuit board off, I just lifted up on the EL transformer and used a flat bladed screwdriver to gently slide the circuit board up and off the header connector on the bottom right.

Up and off.

Now you can get to the display. Unsolder the two leads going to the circuit board. There will be some glue that you will have to remove that’s holding the back light in place. I just used a small flat bladed screwdriver to scrape it off, then you can slide the backlight out from behind the lcd panel. You can see the old backlight in the picture below. I had positioned a white piece of paper in it’s place so I could experiment with LED backlighting.

Here you can see the new EL panel I bought as a replacement. This is a Lumitek that I came across on Ebay for $6. I used the old backlight as a template and trimmed it to size with a pair of scissors.

Trimmed to size. This is actually the back of the EL panel, the other side is the part that illuminates. Don’t ask how I know this but lets just say that my first try at this I thought the EL panel was bad until I noticed a nice blue-green glow coming from inside the scanner. I installed it backwards…

Test fit before soldering the leads in place. The panel is powered by A/C so polarity doesn’t matter when you solder the leads to the circuit board.

Finally, reposition the circuit board back in the face, making sure to line up the sound squelch led. Replace the screws, solder the ground connection, and reverse the dis-assembly steps. You should have a nice new bright backlight for this classic scanner.

I ordered EL strip from Hong kong via Ebay, I had to cut the strip to size but when I powered up the scanner there were thick black “shadows” round the edges I’d cut, in places so thick so as to obscure some of the display info. Did I do something wrong or is it just a poor product I bought?

Hey Clive, sorry for the long delay in replying! I’m not sure what happened with your EL strip since I’ve only done one of these. Is the dark area uniform around the whole panel like it is undersized or something? I have a bit of a dark rectangle in the top left corner of mine where one of the terminals is attached that you can see if you look at the display at an angle from the right. One of these days I’ll open mine back up so I can slide the EL panel a bit to the left so you can’t see it.

Dave, do a search on eBay for EL panel and you should be able to find something. I’m looking at one right now for around $9 with shipping from China that would work (eBay seller oywendy2011) . Shoot me an email if you can’t find anything. FYI, I just measured my stock backlight and it’s 25mm x 85mm so don’t get anything smaller. Good luck!

hi – i work for a UK el panel company and we are planning to make some of el panel replacement backlights
ideally we would like ones that fit into several different models
can you tell me if the 25mm x 85mm is the lit size or the total size of the panel?
is thart a standard size for different Realistic models?
we are hoping to make a panel with exactly the right width and so it is very simple to cut to length for the particular model

TIPS FOR CUTTING THE EL PANELS
wherever you buy these panels please remember:
1) always cut with sharp scissors – a scalpel blade will not cut through cleanly enough and may cause delamination(where you see bruising as clive found)
2) always seal the edge afterwards with something like superglue or nail varnish to stop moisture getting inside the sandwich layers of the panels

Hi Dave,
The 25mm by 85mm is the actual size of the original EL panel. There is quite a bit of leeway on the width, but not the height. The illuminated area is a bit smaller, approximately 20mm by 78.5mm but I’ll have to take a couple of more measurements and a couple of photographs and I’ll post them for you. I also have a PRO-2037 that seems to be the same size, and a Pro–2021 that is the same height but longer width. Give me a day or two and I will have some more info for you.

thanks – thats great timing too cos today someone else has actually sent me a panel taken from a PRO 2006
the entire panel is 25mm from top to bottom and i guess it needs to be that size to exactly fit
the el part of the panel is 21.5mm across and has a non-lit thin electrode that runs the length – about 1mm from the top
this electrode must sit outside the visible area and i guess there will be about the same width at the bottom that is also outside the lit area
thanks for your help

– so is it possible to give me a real exact width of the lit area? – i know these are hard to measure as there are usually reflectors to make it appear wider
(its cos we will not just copy this one – but redesign it to be better and hopefully give them a thicker top electrode if possible)

I have had a strange problem with my Pro-2006 backlight replacement. When I have replaced the panel (2 different types) the light will turn but it is not bright. I even bought another scanner for parts (it is working) and used the donor pcb3 and still got the same result. Then I took the donor pcb3 and put it back in the original scanner and the EL is still dim. One of the EL’s I got from the guy on Ebay and the second I got from Miller Engineering. So I am stumped. I have had a dim display with new ELs for years. Does anyone have any ideas? Thaniks and 73

Another idea is to look at a company called Miller Engineering. I also bought from him. Here is the email that he sent me with the details:

Hi John,
The EL lamps you want is is out 4301 and the length is 3.75″ have correct the web site. many, many people have use this EL for their Radio Shack scanner. You can see it at the bottom of the page at:http://www.microstru.com/Experimenter-Kits.html
Sincerely,
Chris
miller Engineering

yes we got them in and have been testing them
they are pretty much exactly the same as the ebay item listed above
(with a few notable improvements that i would go into in detail if anyone is interested)
so far we found that these still worked ok as a backlight
but disappointingly are not as bright EL Panels usually are
and for that reason we’re holding them back from sale
– we think the reason is the inbuilt inverter used to power the el panel has been set to an unusual frequency to prevent radio interference

tbh we’re stuck – we can’t really find a way round it at the mo – and don’t want to sell a product we feel should be better

Thank you so much for the detailed replacement procedure. I have a PRO-2005 and obtained the EL panel on ebay from abakuscom. Not being familiar with the EL panels I was concerned about cutting the panel to fit. No problem, the panel can be trimmed both horizontally and vertically without a problem.

It led me to discover another issue with the scanner. It runs really hot! I’ve ordered a miniature fan to help cooling.

After putting up with a dim display for years, I ordered a replacement panel from Miller Engineering. I got it two days later, trimmed to size and expertly installed it backwards. (Hint: Blue side goes toward board!). I flipped it over and all was good. This was a snap! Thanks for the expert advice! Thanks! Bob W8IJG

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Hello NR8O,, I replaced the EL Lamp in my Pro-2006,,With new strip,EL,,and it was still ,not lighting up,,I Measured the EL voltage it was around ..40VAC,,I know EL needs around 80-90 VAC,,Any idea what circuit may be bad,EL Power transformer,Transistor or Capacitor or something,,,Thanks,,,,

Thank you for the eBay link, unfortunately I can’t do eBay purchases. Which is why I was happy to read on here that there was a “perfect” EL panel available at Amazon. I did send Kenneth an email, but never heard back from him. I don’t understand why he couldn’t have just posted the link

The EL Power supply in PRO-2006,,Produces around 90-115 Volts AC,,The Power inverter supply can fail,,My unit failed and it sent around 4-50Volts AC,It Bearly lit the EL-Light,EL Panel Lamps need this inverted voltage around 90-110 VAC to be produced by the PRO-2006 Power Inverter Circuit ,Or I ordered a Mini Power Inverter to power my EL Panel-Lamp,Its brite,,and you can wire it to the 12VDC power supply inside the Pro-2006,,Then to a rear mounted Switch,,Or modify the front switch to function,But needs to be 11-12.9Vdc input to a 90-110VAC output side of Mini Power invert,There around $4.00 on EBAY,,,good luck,, (PS-I have another PRO-2006,It,s Inverter is at 50VAC,,and is DIM,on High Briteness,,The EL LAMP is ok,I sub,ed in a Inverter Power supply @ 95 VAC and its,,looks great,,,Brite,,,Not overly Driven on VAC,,,,

Hi, congratualtions on a great article, well written and with photos to match.

However, it seems electroluminescent panels have a short life span compared to LEDs. With the EL Panel removed, what is the distance between the rear of the LCD panel & the PCB? Can I fit Acrylic (with LEDs) and a diffuser in that gap?

The Pro-2006 Service Manual is downloadable and has all P/Ns for the components comprising the on-board Inverter. Inverter’s Transformer might be difficult to source so my recommendation is always get a 12V Inverter along with your EL Panel that way you’ll have it if the on-board is too weak.

I have replaced a few of the electroluminescent sisplay on the pro 2006 Plus I have seen some borched attempts to use led,s to try & lluminate the back of the display.I fail to see how conventional led,s will fit in the area occupied by the electrluminescent display & give even coverage. There are several colours available the aqua colour blue will be brighter than the mid or dark blue . So choose the lighter shade if you want a brighter display.I have only had one failed inverter circuit & that was down to the switching transistor being faulty. I did try running a switching 12v module.Yes it was brighter but it introduced mush into the scanner received circuits & was not the saviour I thought it would be. I have had no problem useing a scissors to cut the panel to size .